Messages

1

AGI Development Tools / Re: AGI reverse engineering with AI

« on: July 15, 2026, 05:18:25 AM »

I bought a C64 Ultimate as soon as they were available and it's a great machine and I want to explore it a lot more. You can drive up the CPU speed and it also has a built-in REU, both of which may be necessary.

The main challenge in getting AGI onto the C64 is graphics. From what I understand, both the bitmap modes and the character/tile modes are insufficient to accurately display a full EGA picture, due to limitations such as the number of allowable colours. Additionally, the C64 is really designed more for tile-based graphics (40x25 I think).

I saw an interview with Ron Gilbert once discussing the development of the C64 version of maniac mansion. Apparently when creating the artwork they started out with a detailed image and then had to reduce it down to something that could be expressed in at most 256 tiles. I reckon the most promising approach is to not have the engine actually run all the drawing commands in-game, but rather to have a conversion tool which pre-renders and picture into tiles, and then builds disk image(s) containing the converted resources. The priority screen will be tricky though.

I don't know anything about how the Apple II interpreter worked (i know this was used for KQ at least). It might be easier to try to port that to the C64 instead. Either one would be a fun challenge.

2

AGI Development Tools / Re: AGI v2.230

« on: July 15, 2026, 02:01:36 AM »

I made a separate post about my recent reverse engineering experiments, but I fed the v2.230 interpreter to Codex and had it compare with the other versions.

Here is the commit it made, documenting the differences: https://github.com/peterkelly/agi-re/commit/4e53168e817f6dd9bfaad2687e990f896224ff7f

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AGI Development Tools / AGI reverse engineering with AI

« on: July 15, 2026, 01:24:14 AM »

Hey all,

Like everyone else, I've been experimenting a lot with AI coding assistants lately (specifically Codex), in particular trying to explore their limits on difficult tasks. After some promising results seen with reverse engineering C64 binaries, I thought I'd have a go at doing the same for AGI. Everything in the docs linked below has been generated from scratch, given only the executable files and game data of AGI games, without consulting any existing documentation or implementations (SCUMMVM, AGILE etc). My goal was to see what it could do given a completely unknown binary.

While none of the work it's produced is novel (this is all well-trodden ground thanks to the work of the community), I've been able to get it to generate an *extremely* detailed analysis of every aspect of the interpreter and produce a high-level spec, including coverage of different subsystems and different interpreter versions ("profiles"). There's only a few outstanding details left but I think it's pretty close now.

I'm currently having it generate playthroughs of games based on analysis of the logic scripts and use of the QEMU debugger to interact with the interpreter. Once I have winning playthroughs for all games, I'll use that as a corpus for validation and see how well I can get codex to produce a new implementation of the interpreter in Rust.

Spec: https://peterkelly.github.io/agi-re/spec/

RE documentation: https://peterkelly.github.io/agi-re/docs/

Github repo: https://github.com/peterkelly/agi-re

4

The Games and other Sierra Adventure stuff / Re: Playing around with AI Image Conversion on Sierra titles

« on: March 24, 2026, 11:31:36 PM »

I'd actually be interested in seeing how things go from the other way around - e.g. taking a photo of a real location and then generating a 256-color or 16-color image for use as a background in a game, with adjustments made as necessary to ensure things like walk paths and item hotspots are of a suitable size. Could be very useful for making fan games, replicating the style & charm of the originals. And I don't expect it would be too technically difficult; AI's involvement would be minimal here, basically just deciding what tweaks to make to the downsampled image, and ensuring stylistic consistency between all the images in an area/game.

Also FWIW I agree with Collector's point about AI & art for existing pieces, though I think these tools are promising for new games, esp. fan stuff like AGI/SCI where most of us simply don't have access to the time/resources/talent required to make a high quality game all by ourselves.

5

The Games and other Sierra Adventure stuff / Re: Ken and Roberta's old Oakhurst house available to book on booking.com

« on: July 12, 2025, 11:40:00 AM »

Lance - you just got a shout-out from the Legends of Adventure team for alerting them to the fact it was available on AirBNB. They were apparently able to visit and get some footage there for the documentary: https://www.backerkit.com/c/projects/legends-of-adventure/legends-of-adventure/updates/25332#top

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The Games and other Sierra Adventure stuff / Re: Back in development: V - Resist or Perish

« on: March 25, 2025, 06:58:56 AM »

Looks nice! Always great to see active development still happening on AGI games!

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The Games and other Sierra Adventure stuff / Re: King's Quest 4 - Did you know they replaced background pictures??

« on: January 31, 2025, 01:50:36 AM »

Jeff Stephenson discusses how he ported the AGI interpreter to the Apple IIe at 55:00 in the following interview:

https://youtu.be/K3s0nW1FBN8?si=0iYqh4iMUEm8Vnkz&t=3300

8

AGI Development Tools / Re: Any AGI engine upgrade projects? Looking for better graphics.

« on: December 05, 2024, 09:28:11 PM »

Kawa, I was just browsing through the files in your SCI stash and in original/TOOLS.zip I found the following, which I was not aware of previously:

Code: [Select]

ATOS.EXE     - AGI to SCI source code translator
It seems to work when run against some of the original LSL1 files. Not sure if the resulting code compiles, but interesting to see that they actually had developed such a tool. I wonder what it was used for?

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The Games and other Sierra Adventure stuff / Re: KQ6AGI - Complete after 18 years of development!

« on: August 22, 2024, 02:36:08 AM »

Damn, that's some serious dedication! This is probably the largest game ever done in AGI. Nice work!

10

The Games and other Sierra Adventure stuff / Re: New Sierra Documentary In the Works

« on: August 07, 2024, 11:35:44 AM »

Something that I've been thinking about for a while now is an integrated online editor and interpreter for AGI games, and with AGILE now running in the browser, I guess my approach would be to extend that. Obviously that is quite niche though, and only a handful of people are ever going to use it

As an experiment to try out the idea and see what it would be like, I think this is something worth considering, even if the actual implementation won't necessarily be of interest to a lot of people. In part i got this idea after learning about Smalltalk's interactive programming environment. The ability to edit code and see changes in near real-time has also been an issue that I've wanted to explore as part of a workflow language/engine I've been working on for several years (which was built for a company I worked for but will soon be open sourced). So I'm interested in exploring this in the general sense and AGI happens to be a convenient vehicle to do so, particularly given we already have a working interpreter, compiler, and other tools that could be leveraged.

You seem to be thinking of something new that will capture a modern audience, but perhaps in the same spirit as AGI and SCI. I think that the online collaborative editor and interpreter would be a key part though, something similar to what kids use in schools these days, e.g. Scratch and Construct3D, where they have an account and can build away, save, execute directly in the browser and share. I'd say yes to the simple scripting language as well, it could even be visual in nature, such as with Google Blockly, whose demos show switching between source and visual, which I think would be needed for people who like to code quickly directly in the source.

Yeah I'm mostly brainstorming ideas at the moment, haven't decided on any specific course of action. I think a new engine/development system would be something interesting to try but only if there's something particularly new or different relative to other things that are out there currently. But AGI is a nice, simple system with which we're both familiar and it sounds like you've been having similar thoughts to me regarding an integrated editor/interpreter.

11

The Games and other Sierra Adventure stuff / Re: New Sierra Documentary In the Works

« on: August 07, 2024, 08:41:16 AM »

The other thing that was really cool recently was the Adventure Game Fan Fair. I didn't attend, but I watched some of the streams online. It was great to see the former Sierra employees speaking in the various panels, including Bob Heitman in a couple of them. Always great to hear what he has to say. I think that his memory of those days is second to none. I have my fingers crossed that since the team behind the documentary were at the Fan Fair that they will have spoken to Bob about being involved in the documentary as well. They already have a rather impressive cast of ex-Sierra employees lined up.

I don't know how I missed out on this, since I would have considered going, but like you I did watch the videos after the event. Was also quite interesting to hear from Bob Heitman; there was one comment he made in particular that struck me:

"A goal of mine for years - and I don't think I'm going to realise it, because it takes a lot of effort still - is to return game development, at least adventure game development, to a one or two person format. Something, a set of of tools - I can't really phrase how they'd be written - that would put the power of creating games back into the hands of one or two people who just have an idea and they want to get it out there, but they can't affort 20-50 million dollars put their game out there to entertain people. That's something that I still want to see somebody do."

(timestamp 2:40:28 at https://www.youtube.com/live/gjrSZmnzOxI?si=GddV5rTVY1pqEzF-)

I found this quite interesting, since on the one hand he makes a good point, but also there's quite a lot of tools available these days that do make it easier, though none that I'm aware of that can come close to matching the state of the art being produced by AAA studios; for indie devs producing pixel art games there's a lot more available, both in the adventure game world and others.

It does make me wonder though, what might a modern adventure game engine and development environment, one designed for today's technological capabilities, look like? I'm "between jobs" right now and hunting around for something to do to fill my time and feel kind of tempted to have a go at this, but I'm curious to hear what others think of this. A few ideas - 3d world, procedural generation of graphics and/or some game elements, a nice & simple scripting language, interactive programming (game world updates as soon as you change it, no compilation), publishing to web/native, online play and online collaborative editing. Just a few random ideas, but I'd love to hear yours.

12

The Games and other Sierra Adventure stuff / Re: 40 years ago (KQ1/GAL/AGI)

« on: May 11, 2024, 12:42:55 AM »

Roberta Williams - King's Quest 40th Anniversary

13

AGI Development Tools / Re: The web version of AGILE (https://agi.sierra.games)

« on: May 08, 2024, 10:08:46 AM »

Also

https://www.reddit.com/r/Sierra/

https://www.reddit.com/r/adventuregames/

https://news.ycombinator.com/

14

AGI Development Tools / Re: The web version of AGILE (https://agi.sierra.games)

« on: May 08, 2024, 10:05:03 AM »

I recommend contacting the Space Quest Historian (https://spacequesthistorian.com/). You might even be able to convince him to make a youtube video about it, or perhaps a livestream.

15

AGI Development Tools / Re: The web version of AGILE (https://agi.sierra.games)

« on: April 26, 2024, 10:00:35 AM »

Regarding the keyboard: I was initially thinking that having the toggle button for showing/hiding the keyboard visible at all times would be a good approach, then the user can choose. Then I had another idea which I think would be even better for mobile - what about an SCI-style approach where the input window is visible only when you want to enter a command? For devices with a keyboard (desktop or ipad with bluetooth keyboard) this would be triggered by pressing any letter (which would appear as the first character of the command). The user can also click/touch the input line (still visible, or with a "click to type" text or similar) to bring up the text input window.

If you use the browser's native text input mechanism (by temporarily creating a form on the page with a text input field), this would then allow the user to use the keyboard built-in to the OS, which may be easier to use than the custom one in AGILE. I'm not sure how difficult this is given the way the web-based version of the engine works though.

Will get back to you later on the Safari version (wife is currently using the iPad).